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Sunday, November 11, 2018

Today I am
going to talk about the Access lists. An access control list (ACL), with
respect to a computer file system, is a list of permissions attached to an
object. An ACL specifies which users or system processes are granted access to
objects, as well as what operations are allowed on given objects or you can say
for each rule we have two conditions and that is Permit or Deny.

Types of Access Lists

There are
two categories of access lists: numbered and named.

Fig 1.1- IP access Lists

Numbered Access Lists:-

Numbered
access lists are broken down into several ranges, each dedicated

to a
specific protocol:

1–99 IP
standard access list

100-199 IP
extended access list

200-299 Protocol
type-code access list

300-399
DECnet access list

400-499 XNS
standard access list

500-599 XNS
extended access list

600-699
Appletalk access list

700-799
48-bit MAC address access list

800-899 IPX
standard access list

900-999 IPX
extended access list

1000-1099
IPX SAP access list

1100-1199
Extended 48-bit MAC address access list

1200-1299
IPX summary address access list

1300-1999
IP standard access list (expanded range)

2000-2699
IP extended access list

Named Access Lists:-

Named
access lists provide a bit more flexibility. Descriptive names can be

used to
identify your access-lists. Additionally, individual lines can be

removed
from a named access-list. However, like numbered lists, all new

entries are
still added to the bottom of the access list.

There are
two common types of named access lists:

IP standard
named access lists

IP extended
named access lists

Standard IP
Access List

Standard IP
access-lists are based upon the source host or network IP address, and should
be placed closest to the destination network.

The above
ip address is just taken for the example and don’t have real environment existence.

The first
line allows the 172.18.x.x network access only to port 80 on the web server.
The second line blocks 172.18.x.x from accessing anything else on the
172.16.x.x network. The third line allows 172.18.x.x access to anything else.

To apply
this access list, we would configure the following

Router(config)#
int e0

Router(config-if)#
ip access-group 101 in

Extended IP
Access List Port Operators

In the
preceding example, we identified TCP port 80 on a specific host use the
following syntax:

Friday, November 9, 2018

Today I am
going to talk about the basic configuration of H-VPLS. The IP addresses in the
topology are the loopbacks of the U-PE/N-PE devices. The IP addresses of the
Clients are what we expect to look direct connected via the H-VPLS core.

Under
normal circumstances I would expect the N-PEs to all be a part of the same ISP
BGP AS, and the U-PE boxes to be in different BGP AS’s.This would require some type of BGP Inter-AS
option to extend the LSP between providers.To keep it simple I just configured
a single core and enabled MPLS for the label switched path.